When Space Drugs Go Bad

While traveling along on your way to Mars, you realize you had one too many Romulan Ales on your day off and have woken up with a blazing headache. You float over to the med cabinet, pop a few aspirin and get back to repairing the turbo encabulator. But after a while you realize your headache is still there. The meds didn’t do a thing.

Hopefully this won’t happen thanks to Lakshmi Putcha’s group at NASA Johnson Space Center (JSC) who recently published research on the stability of medications after long term space flight. They found that many of the common medications carried on the International Space Station (ISS) lost their potency compared to those stored on Earth.

Some Reds, Some Blues, Some Powders, Some Glues…

This ISS medicine cabinet is stocked with a variety of almost 200 meds such as: antibacterials, antiviral, antifungal, decongestants, motion sickness, antidiarrhea, Tylenol, etc. All of these are contained in a compact bag made more lightweight by repackaging some of the items into lighter bottles or bags.

The drugs are routinely exchanged every six months or so to prevent against accumulating a kit full of expired drugs. This kind of exchange will not be possible on a long term mission, so the lab at JSC wanted to test if there were any long term effects to pharmaceuticals on extended space flights.

Putcha’s lab made eight kits, each with 35 of the most common creams, liquids and tablets found in the ISS medicine kit. Four kits were kept at JSC as unflown controls and the other four were stored on the ISS, transported via the shuttle. One kit each was returned over four shuttle missions, with the shortest kit flown for 13 days and the longest for 880 days (2.4 years). All of the kits had radiation dosimeters along with humidity and temperature measuring equipment.

Using a slew of assays the researchers tested for physical and chemical changes to the medications. The humidity and temperature data for JSC and space had a few disparities, but overall were comparable and within limits. Yet the chemical assays showed the space flown kits had significantly less pharmaceutical punch than the ground kits.

According to Dr. Putcha and her group, this difference between the ground and flight kits is best explained by the large radiation dose experienced by the kits that flew longer on the ISS. The kit that flew for all 880 days experienced a whopping 110.7 milliGray (mGy). A typical CT scan is about 1 to 10 mGy and a instant whole body exposure of ~5 Gy will kill you (or at least make you like this).

Bar Graph of Radiation Dosimeter data. Notice how dose of flight samples increases with time, from left to right.

The majority of radiation in space consists of fast moving protons and heavy ions that rip off electrons as they hit material, leaving a trail of ionized particles that damage everything around it. It may come as no surprise then that the researchers found that the light (a form of radiation) sensitive meds fared the worst.

On Earth, these drugs are usually protected from light by storing them in foil packets or brown bottles, but since radiation in space is much stronger than visible light, the bottles and foil can actually create a burst of secondary radiation. The results also showed that the solids fared slightly better than the liquids.

What now Captain?

While the United States Pharmacopoeia recommends a drug’s shelf life based on limits of humidity, temperature, and visible light exposure, relatively little is known about the effects of powerful cosmic radiation on them.

It appears from these preliminary results that better packaging may be required for longer duration flights, especially missions out of the protective layer of low Earth orbit.